Hydrocarbon conversion



Jan. 2, 1945. A. BELCHETZ ET AL HYDROCARBON CONVERS ION Filed oct. 22, 1942 IIIJ QS .95k vm N MW n m QS@ .QS una. NN

Patented Jan. 2, .1945

UNITED STATES' HYDBOCARBON CONVEBSION v Arnold Belchetz, Larchmont, and Myrle M.

Perkins, Plandome, N. Y

., asslgnors to The M. W. Kellogg Company, Jersey City, hl. J., a corporation of Delaware' f Application OctobcrfZZ, 1942, Serial No. 463,012.

scann. (c1. 26ocsail This invention relates to improvements in the production of oleiin polymers. More particularly, the invention relates to improvements i the process in which olen hydrocarbons are iirfst absorbed in a liquid acid polymerizing catalyst and the extract is then heated to polymerize the absorbed oleiins.

Olefln hydrocarbons may be absorbed at relatively low temperatures in liquid acid polymerizing catalysts such as sulfuric acid or hydroiiuoric acid, and the absorbed oleilns may then be polymerized by heating the extract to a suitable polymerizing temperature. The -principal commercial useof this process is the cold acid polymcrization of isobutylene. In this process isobutylene is absorbed in sulfuric acid of suitable concentration at relatively low temperature, and the extract is then heated to a suitable polymerizing temperature to separate the absorbed hydrocarbons as polymers and regenerate the acid catalyst. Iso-olens such as isobutyleneare more readily absorbed by the acid catalyst than normal oleilns, so that by maintaining contact of the acid and the .oleiins at relatively low temperature and by limiting the time of contact the isooleiins such as isobutylene may be absorbed selectively from a hydrocarbon mixtme containing:

normal olens such as normal butylenes.

Afterthe extraction step the olen-acidextract is separated from any unabsorbed hydro-V carbons which may be present, and the extract is then treated to polymerize the olens and regencrate the acid. This may be done by heating the extract to a temperature sulllciently high to polysubstantialA cross-sectional area. Such a reacmy be lead lined and acid-brick lined and iilled with suitable acid resistant packing such as ceramic Raschig rings. Insuchan alglparatly problems of corrosion and erosion are substan- The extract is polymer.I A

isingtemperatlrrebygiihittherequis iteguantity oi.' the hotillkl The heating fluid prior to Contact with the extract-snowman is condensed by contact .with the extract, whereby the heat necessary to raise the temperature of the extract to the polymerizingrtemperature is supplied at least inv part by the heat of con- Low-boiling saturated paraiiin hydrocarbons such as the butanes are advantageous heating fluids because ci their relative inertuess.l However,

low-boiling olen hydrocarbons such as the butylenes may be employed ii the polymer products lproduced by the reaction of such olen heating j iluids are tolerable in the polymer product of the process. The selection of a suitable heating fluid is not-limited', however, to hydrocarbons, as any suitable iiuid may be used which does not form' M undesired reaction products. Suitable heating fluids other than hydrocarbons which may be employed include the ethers, such as dimethyl ether and diethyl ether, and alkyl chlorides, such as methyl chloride and ethyl chloride.

In the polymerization of olen hydrocarbons Y -it is desired ordinarily to operate under comditions which promote the formation of dimers and minimize the production of trimers and quadrimers. For example, in the polymerization of 3 isobutylene to :om ui-isobutylme for hydrogenation to iso-octane it is desirable to'operate vunder conditions which minimize the formation Vof polymers other than dimers. Furthermore, dimers are preferable to trimers in a polymer feed for an alkylation process since the consumption of acid in -the alkylation process is lowerv when 4 alkylatin'g dimers than when alkylating trimers. It is desirablathereforatoheatthe extractrapidly to the temperature at which #otheproductionofdimersrather/thantrimersis favoreilimittheholdingtimeatthatpolymerlxingtothat ntoettect maximum Ionnaiionotdimersandthen quickly lowertheottberactionmixtureto mepoinntvmchuonissunstanuany inhibited. Rapidcoolingoi'thereactionmixture umxereaconmneislealso tocooltbeaddtoatemperaturelowenoushto corrosim in themequipment through .wwhichtheacidplssestlytoitsemergenceimmthereactlonaune.

Inwlththeinventlonrapi coolingoftheregctlonmixtureinamanner whichinvolvesthleastcontactoithehotacid# selectedpreferablyisonegliidigmybevaporlsed with apparatus subject to corrosion to a relatively low temperature.

by vincorporating in the reaction mixture a liquefied fluid which is lower boiling than the polymer product and then releasing the pressure on the mixture to permit vaporization of at least a portion of the liquefied fluid so that the unvaporized remainder of the mixture is cooled The liquefied low-boiling fluid may be admixedwith the reaction mixture as it emerges from the reaction zone or may be incorporated in the reaction mixture prior to the entrance thereof into the reaction zone or during passage of the reaction mixture through the reaction zone. `The vaporized duid is separated from the unvaporized remainder, and the vapors are liquefied and returned for further use in the process.

'Ihe liquefied uid which is admixed with the reaction mixture should be substantially lower boiling than the desired polymer product in order to minimize vaporization of the latter when the pressure on the mixture is released. The liquelfled fluid preferably is admixed with the hot reaction mixture emerging from the reaction. zone while at a relatively low temperature in order to effect a preliminary quenching' of the mixture prior to the release of the pressure.

Preferably, a liquefied cooling fluid is selected whichl has boiling characteristics generally similar to those of the olefins absorbed in the extract. The pressure on the reaction zone ordin'arily is maintained sufilciently high to prevent vaporization of the absorbed olefins which may be regenerated from the extract by the polymerizing temprature. Therefore, the use of a cooling fluid of boiling characteristics similar to those oi' the absorbed oleilns is advantageous since it does not require the application of a higher pressure on the reaction zone to permit mixing the liquefied cooling fluid and the reaction mixture in` the liquid phase. This relationship in boiling characteristics is not essential, however. since any liquefied cooling fiuid may be used under conditionswhich permit mixing of the liquefied uid and the liquid reaction mixture followed by vaporization of the liqueed cooling fluid upon releasing the pressure on the mixture.

Ordinarily, a substantially non-reactive material is preferred for use as the liqueed cooling fluid. For example, low boiling paramn hydrocarbons such as propane. the butanes and the pentanes are preferred. Higher boiling parain hydrocarbons are satisfactory if the boiling point of the polymer product is suiciently high to permit separate vaporlzation of.' the cooling fiuid. Lower boiling parailin hydrocarbons require the application of a very high pressure to effect their liquefaction. are satisfactory Aalso if, the polymer products which they may form may be tolerated in theA product of the process. Liquefled fluids other vthan hydrocarbons may be' employed also such as dimethyl and diethyl ether and methyl and ethyl chloride.

Conveniently, the material employed as the liquefied cooling fluid may be identical with material employed to heat the extract to the reaction temperature. For example, in the polymerization of isobutylene the extract may be heated to the reaction temperature by mixing therewith vaporized isobutane in such proportions as to produce a resultingliquid mixture at the desired polymerizing reaction tempera- Lw-boiing olefin hydrocarbons leased to permit vaporization of a substantial proportion of the isobutane in the mixture to effect cooling of the remainder of the mixture.

Conveniently, vapors thus obtained are condensed, and condensate thus obtained is admixed with the reaction mixture emerging from the reaction zone prior to the release of the pressure to quench the reaction mixture to a lower temperature. In carrying out the process of the invention in connection with -a ypolymerization operation employing a liquefied heating fluid it is advantageous to employ a similar material as the cooling fluid in the manner just described to avoid introducing the multiplicity of different materials into the reaction mixture.

` The invention Will` be described in more detail by reference to a specific application of the invention to cold acid polymerization of isobutylene. It is to be understood, however, that the invention is not limited to processes involving polymerization of iso-'oleflns but includes within its scope the polymerization of any olefin hydrocarbon having the same 'or a greater or less number of carbon atoms per molecule and is applicable also to the polymerization of olefins rother than iso-olefins such as normal olefins and as the liquid acid polymerizing catalyst. It is to be understood, however, that the invention is not limited to the use of this specific catalytic agent but is applicable to -processes employing other liquid acid catalysts, such as hydrofluoric acid.

Inthe further description ofy the invention reference will be made by way of example to the accompanying drawing which illustrates diagrammatically an assemblage of apparatus for carrying out the specific application of the invention to a process involving the polymerization of isobutylene. It is to be understood, however, that the invention is not limited by referenceto a specific assemblage of apparatus since the principles of operation illustrated are applicable to the polymerization of other olelns by means of other combinations of apparatus and operating steps and by means of liquid polymerizing catalysts and operating conditions other than those referred to specifically. 'I'he invention will be described also by reference toits preferred modification in which polymerization of the absorbed olefins is effected by mixing with the extract a vaporized heating fluid which forms with the extract a resulting fluid mixture at the desired polymerizing temperature. In

this preferred modification of the invention a material similar to the heating fluid is employed as the cooling fluid in the manner described above. The invention, however, is not limited in its application to polymerization processes in which the extract is heated to the polymerizing temperature in the manner described nor is it ture. After the emergence of the resulting reaction mixture from the reaction zone. and with limited to the use of cooling uids similar in composition to materials which may be employed in the polymerization step as heating fluids. Y

Referring to the drawing, the polymerization process is carried out in reactor I which is an elongated lead-lined acid-brick lined cylindrical vessel adapted towithstand the application of substantial pressure.,y Preferably,l reactor l is I through line 5, provided with a pump 6, which connects with accumulator l. From accumulator filled with somesuitable acid-resistant packing such as ceramic Raschig rings.

'Ihe acid-isobutylene extractis supplied to the operation through line 2, which is provided with a pump 3, by which the extract is introduced into one end of a lead-lined mixing nozzle I which communicates at its other end with the interior 'of reactor I.

The heating fluid is introduced into the system 'I heating fluid is withdrawn throughline 8, provided with pump 9, and introduced into mixing nozzle 'I at a point adjacent the'point of introduction of the extract through line 2. Heating means l is provided in line l to heat the heating fluid `introduced into nozzle l `to vaporize it ,and superheat it to the desired degree. Y

AThe heating fluids which are most suitable for use in the polymerization of 'isobutylene are isobutane and-normal butane. Normal butane may be used without the maintenance ofra higher pressure on reactor I than would be requiredto prevent vaporization of isobutylene.' but, on the other hand, it requires heating to a higher temperature atlll to vapori'ze it than does isobutane.

an alkylation operation,- the use of isobutane asV the-heating fluid is advantageous since its presence in the polymer product does Yno require fractionation' of the, product prior to charging the 'polymer vto the alk'ylation process'. VIn accordance with this specic example, therefore, isobutane is accumulated at 'I and charged into mixing nozzle 4 at the desired rate'aiter having been vaporized at I0. s Y

The amount of isobutane required for polymerizing each unit of isobutylene charged to the 'system inthe extract through line 2 increases as the concentration of isobutylene in the extract decreases. The molar'ratio of H2804 to CiHa in. the extract mayvary from 0.5:1.0 to 4.0:1.0.

Preferred methodsof extraction of isobutylene for'the polymerization step'ordinarily result in supplying to the latter an 'extract in which the molar ratio of H2804 to CiHa is` in the range ofl 0.7:1.04to 1.0:1l.0. Higher ratios of acid to isobutanlncreasethe heat requirement of the polymerization step substantially and lower the eiliing'fluid somewhat lower pressures could be employed in the reactor since isobuty'iene -would be the lowest boiling constituent of the mixture. Preferably, the pressure on-the reactor is maintained somewhat above the indicated minimum. When using isobutane as the heat iluid the operating pressure should vary from'200 pounds per Vsquare inch'(gauge) at 170 F.,to 300po1mds per square* inch (gauge) at210 F.

The amount of isobutane which must be injected into mixing nozzle I to polymerize a unit quantity of isobutylene introduced therein from line 2 is ailected by the concentration of isoi butylene in the extract, the temperature of the extract, the polymerizing temperature selected and the temperature of the vaporized isobutane introduced into the mixing nozzle 4 through line 8.' The heat made available to thepolymerization reaction by the vaporized `isobutane is the latent heat of condensation at the operating pres- A sure, the sensible heat of the sohutane vapors Furthermore, if it is desired to employ the isoi butylcne polymer product as charging stock to resulting from the superheating of the vapors and the sensible heat of the condensed isobutane.-

'I'he variation in the quantity of isobutane required for various operating conditionsY and various concentrations of isobutane in the extract when the'extract flowing through-Unef! is supplied to mixing nomle l at 95' F. and when vaporized isobutane is supplied to mixing nozzle l at a temperature of 300 F. may be summa Y in the following table:4

pounds 4() Heat available per ciency of the extraction operation in extracting,

' isobutylene'in preference to the normal butanes.V

It is preferred ordinarily to maintain the polymerization i zone` at a temperature within the range of to 230 F. to achieve complete re.-

. generationv of the acid and to avoid temperatures :lower thanthe vapor pressure .of the isobutane lPounds of isobutane required to amm 1.o;1.o

al) al) Polymerization temperaturev F Polymeriza tion premlre in h (g per square c auge) pound isobutane l las .t.u polymerize each pound of isobutylene to dii isobutylene 1.23 1.89

`The vaporized isobutane and extract are intimately mixed inmixing nozzle 4 to form a liquid mixture at the preselected reaction temperature. 'I'he reaction 'mixture then flows through reactor I at a rate which provides the holding time necessary to eiect the desired polymerization of isobutylene. 15l minutes ordinarily is` the maximum holding time necessary and 3 to 5 minutesf ordinarily is sulcient. The temperature ofthe reaction vmixture owing. through the reaction zone is substantially uniform as the endothermic reactions by whichc the tertiary butyl alcohol and tertiary butyl esters are converted to polymer is balanced by the exothermic polymerization of isobutylene which is released from the mixture by the heating of the extract to the reaction temperature.

"me introduction of a large proportion of s u low-boiling uuid such as isonutane info the recontained therein, because of the presence-in the mixture of .lower materials such-as polymers and isobutylenegfthe vaporpressure of4 isobutane. whichvaries from. 170 pounds persquare inch (gauge) air-170 F. to 275 `.pounds per square inch (gauge) at 210" is` asatisfactory minimum pressurefor use in the reactor. If

normal butane were to be employed as the'heataotionmixture at I as a heatinguid :and the subsequent condensation of by contact with the extract' is one method of incorporating in the reaction mixture' a'substantial prov'portion .of a low-boiling iluid which may 'be' evaporated from the reactionmix'ture emergingfrom the reaction zone to coolv the remaining unvaporized portion of the reaction mixture. For

, example, the reaction mixture emerging from reactor I through line Il may have the pressure thereon substan y reduced in order to permit evaporation of a substantial proportion of theV isobutane. It is'preferred, however, to subject the reaction mixture emerging lfrom reactor' I y to a preliminary quench bymeans of a low-boilingcooling fluid introduced into the system therethrough is intimately mixed with the re-'" action mixture emerging from reactor I. Cooling means I may be provided for chilling the cooling fluid as desired to eiect the desired degree of cooling in the reaction mixture 'at I4.

Conveniently, the cooling iiuid introduced through line I2 consists essentially of isobutane in order that material introduced through line I2 shall be substantially the same in composition as the heating fluid introduced through line 8 in order to restrict the number of different materials introduced into the system. If isobutane isy employed as* the cooling iluid it may be supplied from accumulator 1 by means of line I6 which connectsl line 8 and line I2. Cooling means I1 may be provided in line I6 for chilling isobutane passing through line I6 to the desired degree. I

Line I I connects with a settler I8 in whichthe acid and polymer' are'to be separated into an upper, hydrocarbon, phase and a lower or acid valve I9, associated with automatic control means 20, is located inline II' to reduce the pressure on the mixture passing through line II to a substantial degree. For examplethe pressure on the reaction mixture may be reduced from alre| action pressure of 300 pounds per square inch (gauge) to a pressure of 50 pounds per square inch (gauge) in settler `I8. The pressure in settler I8 may be varied to control the temperature therein in response to variations in quantity and vtemperature of the reaction mixture and cooling fluid employed.

g The quantity of isobutane introduced at I4 through `line. I2 and the temperature thereof are regulated whereby the reduction in pressure on the. reaction mixture at I9 permits suillcient evaporation of isobutane to produce a temperature in the settler v.not substantially greater than 150 F., preferably reduction of the temperature to 110 F. Should be attained. Ordinarily, the quantity of isobutane introduced through line II at 90 F. to accomplish this result is the same order 'of magnitude as the quantity of isobutane introduced at 4 through line 8 at 300 F. Necessarily, this is anA approximation since the exact quantities required depend upon many factors. In settler I8 the unvaporized liquids separate into an upper or hydrocarbon phase and a lower or acid phase in the portion of the settler to the` left of baille 2|'. The acid phase/ls lwithdrawn through line 22 for return to the absorption'step. The hydrocarbons ilow over baille l2I to the other gestion of settler I8. In `this smaller section of a valve 284 for controlling the pressure ,pn settler The hydro- I8. Line connects with cooling means 21 by meansof which the isobutane vapors are cooled suillciently to condense them. Condensate thus obtained is transferred from condenser f 21 through line 28 to a surge drum 29 in which the condensate is collected.

-The isobutane condensate collected at 29 preferably is returned for reuse through line- 30 which connects surge drum y29 with line I2 whereby condensate obtained at 2S is employed as a Line 30 is provided if' quench medium at I4. necessary with a pump 3| and cooling means 32, the latter being provided to effect any desired chilling of the condensate priorto its use as quench medium at I4.

All or aportion ofthe isobutane condensate.

owing through line ,30 vmay be diverted therefrom through line 33 which connects 1ine-30 with accumulator 1.

As a further alternative method of operation `all or a portion of the condensate collected at 23 may be'returned directly to settler I8 through line 34 which connects line 30 with settler I8. Line 34 is provided if necessary with a'valve 35.4 It is more advantageous, however, to pump the condensate at 29 up to the pressure of reactor I' and employ-it as the quench medium at I4. "v As a further modification of the invention the! I /vapors withdrawn from settler I8 through line 1 30 minimize corrosion diiilculties a pressure control f 25 may be diverted therefrom through line 36 which connects with a compressor 31 by means of which the vapors are recompressed to the polymerization reaction pressure. The outlet of compressor 31 is connected to line 25 by means of line 38 so that the resultingvmixture of condensate and vapors is passed to cooling means 21 for further cooling therein to complete liquefactlon of the isobutane. 'Ihe isobutane conden-v sate at 29 then may be transferred to mixing nozzle I 4 or accumulator 1 without substantial increase in the pressure thereon. 'Ihis method of condensing the vapors withdrawn from settler I8 is advantageous in that it permits cooling at 21 by means of cooling water and does not require refrigeration at that point.

In accordance with a further modication oi the process the heat requirements are still iurheat required for the polymerization treatment of the extract. In this method of operation the isobutane required as heating fluid would' through line 24 is then introduced into neu.

tralizer 40. Alkali introduced through line 4I, which connects with line 24, is intimately mixed with the hydrocarbon mixture in -mixer 42 'to effect neutralization of any acid retained by the hydrocarbon mixture. In n'eutralizer 40 4thev mixture is permitted to separate into an upper or hydrocarbon phase and a lower or alkali phase. Spent alkali is withdrawn from neutralizer 40 through line 43. If desired a portion of the spent alkali may berecirculated for V'fluid inthe present process.

reuse through line-44 whichconnects lines 43 and 4I.

- The neutralized hydrocarbon mixture is with-` drawn overhead from neutralizer 40 through line 45 whichlconnects with fractionator 46.- Heating means 41 may be provided topreheat the` hydrocarbon mixture prior to its entry into fractionator 46. In fractionator 4B the hydrocarbon mixture is subjected to fractionating condi- 10 tions adapted to separate overhead the'isobutane contained therein as well as accompanying ma- `terials of similar boiling characteristics such as unconverted isobutylene. 'I'his material passes overhead from fractionator 45 through line 48 15 which is provided withvcondensing means 49 and which connects with accumulator 50. From accumulator 50 the condensed isobutane is withdrawn through line 5l provided with pump 52.

Line 5| connects with accumulator 1 whereby the go sobutane flowing therethrough is returned for ployed as feed stock for an alkylation'process.

If the polymer product is to be employed in y an allavlation process and if isobutane is employed as the heating and cooling huid in the 35 polymerization process it may be desirable to eliminate. the fractionation step carried out at 45. Allor a portion of material flowing through line 45 may beydiverted therefrom through line 55\for passage directly to analkyla- 40 tion reactor. Cooling means 56 may be; pro-' vided in line 55 to reduce 4the temperature of the mixture to `that of.the alkylation reaction. When operating in this manner the' isobutane required for heatingV and quenching in the poly- 45 merization process may be recovered from the alkylation prooess as a portion. of the isobutane Anormally recycled in that process.

When the process of this invention isem-` f `ploved to separate isobutylene from the fresh 5o feed to a process for making butadiene, the succeeding stages of the later process may furnish a'hydrocarbon mixture which is suitable for use both as a heating fluid andas the cooling liuicl. After treatment of. a gaseous hydrocar-V 55. lbolli mixture essentially 0f C4' hydrocaroons-and including iso-oleiins and normal olehns, to eifect substantial removal of1 iso-olens, the .remaining unabsorbed 4lnrdrocarbon mixture De then subjected t0 lume! eX-f oo traction treatment, for example with acetone, to separate olenns from paraillns. The unabsoroedl paranin mixture from' such a treatment A .,ordmarily. consists ot a mixture of butanes m proportionsl` of isobutane and normal butane a which depend upon the characterof the process in which the gas mixture is formed` If the original' 4feed is obtained 'by thermalcrackingof hydrocarbon oils the butane-mixture vis found to' predominate in normal butane, whereas li a 70 catalytic hydrocarbon oil process is the source m of the gas mixture the butanes predominate I isobutane. In either case this material may be used as the heating fluid and asthejcoonng o Ordinarily. the mixture of normal butaneand isobutane remaining after the extraction Voi olens contains a trace of isobutylene and affew per cent of normal butylenes. these olens in the heating uld and the cooling fluid is not objectionable, however, since any reaction by them results inthe formation of polymers which are included in the polymer. product. 'I'he presence of the-polymers of such olellns in the polymer product is unobjectionable if the latter is to be supplied as fresh feed to .an `alkylation process. If the polymer is tobe hydrogenated to iso-octane the presence of a `small proportion of normal -butenes in the-reactionzone is not objectionable for theI reason that the high proportion of 'isobutylene in the reaction zone will result in cross-polymerization of the normal butylenes with isobutylene with the formation of octanes which can be hydrogenated to a product of high octane number. The use of va gas mixture from this source as the heating iiuid and as the cooling ,fluid in this lprocess is particularly advantageous if the gases are obtained originally from a catalytic process and if the polymer product is to be employed as fresh feed to an alkylation process since. as

pointed out above, such a mixture predominates .y vrin iso-butane.

We claim: g 1. In the method of producing olefin polymersin which olelln hydrocarbons are absorbed inta',V

liquid acid polymerizing catalyst st temperatures below polymerizing temperatures and the extract thusy obtained is heatedvunder pressure to f'a temperature sumciently high, to polymeriz'e the absorbed olens in the liquid phase, the improvement which comprises mixing said extract-'while at a temperature 'below .polymerizing temperatures and at a substantially vsuperatmospheric polymerizing pressure 'with .vapors of a hydro.

carbon, boiling above the polymerizing temperature ati-said pressure, iniproportions .which pro.

-duce a, resulting mixture of extract and condensed vapors which is at the desired polymerizing temperature, permitting polymerlzationto proceed to the desired degree, and then lowering the piessure on said reactior'iI mixture to permit vaporization of-'at least'a portion of said-condensed hydrocarbon vto cool the unvaporized remainder` of said reaction mixtureto a relatively low temperature at which further polymerization is'in-v Y 2. In the method of producing olefinpolymers in which oleiln hydrocarbons absorbed in a liquid acid polymermng catalyst at temrertiufr# below polymerizing temperatures an'd extract thus obtained lis heated under'pressurete a temperature sulllciently high to the absorbed'olen's in theY liquid phase, provement which comprises while at a ltemperature below peratures and :at a `substd. litifally superatinospheric polymeriaing pressure 'with vapors of ia hydrocarbon, boiling jabove the temperature atsaid pressure `butnot' substantially lower than said absorbed olelin hydrocarb'ns,

in proportions which produce a, resulting of extracttand condensed vapors which isatjthe- 'dsir-ed temperature, polymerlmtionto proceed to thedesiredl'dfcgree..y

and then lowering the mixture to permit,V vapozizatlon of at least a tion` of said condensed hydrocarbon' jtd" "fthe 'u ,unvapozedremainder ofsaid The presence of to a relatively low temperature at which further polymerization is inhibited.

' 3. In the method of producing olefin polymers in which oleiin hydrocarbons are absorbed in a liquid acid polymerizing catalyst at temperatures below polymerizing temperatures and the extract thus obtained is heated under pressure to a temperature -sufliciently high to polymerize the absorbed olefnsin the liquid phase, the improvement which comprises mixing said extract while at-a temperature below polymerizing temperatures and at a substantially superatmospheric polymerizing pressure with vapors of a hydrocarbon, boiling above the polymerizing temperature at said pressure, in proportions which produce a resulting mixture of extract and condensed vapors which is at the desired polymerizing temperature, permitting polymerization to proceed to the desired degree, then admixing with the reaction mixture a further quantity oi said hydrocarbon in a liquid condition, and then lowering the pressure on said reaction mixture to permit vaporization -of at least va portion of said condensed hydrocarbon to cool the unvaporized remainder of said reaction mixture to a relatively low temperature at which further polymerization is inhibited.

4. In the method of producing oleiin polymers in which olen hydrocarbons are absorbed in a liquid acid polymerizing catalyst at temperatures below polymerizing temperatures and the extract thus b btained is heated under pressure to a temperature sufficiently high to polymerize the absorbed olens in the liquid phase, the improvement which comprises mixing said extract while at a temperature below polymerizing temperatures and at a substantially superatmospheric polymerizing pressure with vapors of a hydrocarbon, boiling above the polymerizing temperature at said pressure, in proportions which produce a resultingv mixture of extract cool the-unvaporized remainder ofthe reaction mixture to a relatively `low temperature at which liquid phase, the improvement which comprises further polymerization is inhibited.

6.1En the method of producing isobutylene polymers in which isobutylene is absorbed in a liquid acid polymerizing catalyst at temperatures below polymerizing temperatures and the extract thus obtained is heated under pressure to a temperature below the boiling point of isobutane at thehpolymerizing pressure but suiliciently high to polymerize the absorbed isobutylene in the mixing said extract while at a temperature below polymerizing temperatures and at a4 substantially superatmospheric polymerizing pressure with isobutane vapors in proportions which produce a resulting mixture of extract `and condensed isobutane which is at the desired-poly- -m'erizing temperature, permitting polymerization liquid acid polymerizing catalyst at temperatures below polymerizing temperatures andv the extract thus obtained is heated under pressure to' a temperature below the boiling point of yisobutane at the polymerizing v pressure but sumciently high to polymerize the absorbed isobutylene in the liquid phase. the improvement which comprises mixing said extract while at atemperature below polymerizing temperatures and'at a substantially superatmospheric 40 pressure with isobutane vapors in proportions and condensed vapors which is at the desired vpolymerizing temperature, permitting polymerization to proceed to theA desired degree, then admixing with the reaction mixture a further quantity of said hydrocarbon ina liquid condi-` tion,..then lowering the pressure on said reaction mixture to permit vaporization of at least a portion of said condensed hydrocarbon to cool the unvaporized remainder of said reactionmixture to a relatively low temperature at which further polymerization is inhibited, condensingI vapors thus obtained, `and readmixing liquid recovered by said condensation step with the reaction mixture ,as described. v V n 5, Iii/the method of producing butene polymers in which butene is absorbed in -a Aliquid acid alture-below the boiling point of lbutane at the polymerizing 'pressure but suiliciently high to ,ing `said lextract while at ,a temperature below :polymerizing temperatures and at a substantially peratmos'phferic polymerizing pressure with *bita'ne 4vapors'in proportions which produce -a resulting mixture of extract and condensed bu h is atl the desired polymerizing temfperatureRpermitting polymerization of butene to proceed to.the`desired degree'.,a`nd then lowering the 'pressure on the reactin'llmixture to permit vaporization of at leasta portion of the liqueed butane content of the reaction mixture to polymerizing catalyst atl temperatures below p ,polymerizingtemperatures and the extract thus obtained' is heated under pressure to a temperwhich produce a'resulting mixture of extract and degree, then admixing with said reaction mixture a further quantity of said isobutane in the liquid condition, and then lowering the pressure on the reaction mixture to permit vaporization of at least a portion of the liqueiied isobutane content .of the reaction mixture to cool the unvaporized remainder of the reaction mixture to a relatively low temperature at which further polymerization is inhibited.

8. -In the. method of producing isobutylene pol- Aymers in which isobutylene is absorbed in a liquid acid polymerizing catalyst at temperatures below polymerizing temperatures and the extract thus 'obtained is heated under pressure to a temperature below the boiling point of isobutane Aat the polymerizing pressure but sufficiently high to polymerize the absorbed isobutylene inthe liquid phase, the improvement which comprises mixing said extract while at a.Y temperature below polymerizing temperatures andV at a substantially "superatmospheric polymerizing pressure with isobutane vapors in proportions vwhich produce a resulting mixture of extract and condensed isobutane which is at the desired polymerizing temperature, permitting polymerization ot isobutylene to proceed to the vdesired degree.then admixing with said reaction mixture a further quantity of said isobutane in the liquid condition, then lowering the pressure on the reaction mixture to permit vaporization or at least svortlon polymerizing of the liquefied isobutane content of the reaction mixture to cool the unvaporized remainder of the reaction mixture to a4 relatively low temperature at which further polymerization is inhibited, condensing vaporized isobutane thus obtained, and readmixing liqueiied isobutane thus recovered with said reaction mixture after polymerization as/ described.

9. In the method of producing isobutylene polymers in which isobutylene is absorbed in a. liquid sulphuric acid polymerizing catalyst at temperatures below polymerizing temperatures and the extract thus obtained is heated under pressure to a temperature below the boiling point of isobutane at the plymerizing pressure but sutciently high to polymerize the absorbed isobutylene in the liquid phase, the improvement ,which comprises mixing said extract while at a temperature below polymerizing temperatures and at a substantially superatmospheric polymerizing pressure with isobutane vapors in proportions which produce a resulting mixture of extract and condensed isobutane which is at the desired polymerizing temperature, permitting po1ymerization of isobutylene to proceed to the desired degree, then admixing with said reaction mixture a. further quantity of said isobutane in the liquid condition, then lowering the pressure on the reaction mix-ture to permit vaporization of at least a portion of the liqueiiid isobutane content of the reaction mixture to cool the unvaporized remainder of the reaction mixture to a. relatively low temperature at which further polymerization is inhibited, condensing lvaporized isobutane thus obtained, and readmixing liqueed isobutane thus recovered with said reaction mixture afterpolymerization as described.

ARNOLD BELCHETZ. MYRLE M. PERKINS. 

